Sift flour and powdered sugar together 3 times; set aside. Place egg whites, cream of tartar and salt in large bowl; beat until foamy.,Gradually add granulated sugar (about 2 tablespoons at a time).,Continue beating until meringue holds stiff peaks. Fold in vanilla and extract.,______,Spoon batter into ungreased tube pan.,Gently cut through batter with knife.,Bake at 350° for 35 to 40 minutes.,Turn upside down on a funnel; cool 30 minutes.,A 2-piece tube cake pan is best to use.